axi_dmac: Don't add CDC constraints when all clocks are synchronous

When all clocks are synchronous there are no synchronizers and the constraint for the CDC registers can't find any cells which generates a warning. To avoid this don't add CDC constraints when all the clocks are synchronous. Signed-off-by: Lars-Peter Clausen <[email protected]>
analogdevicesinc · Aug 2, 2016 · 6cd0d8a · 6cd0d8a
1 parent 9915234
commit 6cd0d8a
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/library/axi_dmac/axi_dmac_constr.ttcl b/library/axi_dmac/axi_dmac_constr.ttcl
@@ -11,10 +11,12 @@ set req_clk [get_clocks -of_objects [get_ports s_axi_aclk]]
 set src_clk [get_clocks -of_objects [get_ports -quiet {fifo_wr_clk s_axis_aclk m_src_axi_aclk}]]
 set dest_clk [get_clocks -of_objects [get_ports -quiet {fifo_rd_clk m_axis_aclk m_dest_axi_aclk}]]
 
+<: if {$async_req_src || $async_src_dest || $async_dest_req} { :>
 set_property ASYNC_REG TRUE \
 	[get_cells -quiet -hier *cdc_sync_stage1_reg*] \
 	[get_cells -quiet -hier *cdc_sync_stage2_reg*]
 
+<: } :>
 <: if {$async_req_src} { :>
 set_max_delay -quiet -datapath_only \
 	-from $req_clk \